How can I change the HipChat group owner if the original owner has left the company?

The documentation says that if you are the group owner you can change the group owner to be someone else, but what if the group owner has already left the company? I was able to change the owners for rooms, but not for the whole group. What do people do when the person who originally set up the group has left the company?

Earlier this year we made the difficult decision to discontinue our team messaging tools, Stride and Hipchat. The end of life date for Stride and Hipchat Cloud is quickly approaching - February 15, 2...